14th Pisa Meeting on Advanced Detectors KM3NeT : next-generation - PowerPoint PPT Presentation

14th Pisa Meeting on Advanced Detectors KM3NeT : next-generation neutrino telescope under the Mediterranean Sea Rémy Le Breton on behalf of the KM3NeT Collaboration AstroParticule et Cosmologie, Paris Université Paris Diderot 2018/05/28 1 / 24

Introduction : Deep Sea Neutrino telescopes Concept : Detection of Čerenkov light 2 / 24

Introduction : Deep Sea Neutrino telescopes ANTARES Neutrino Telescope : Feasability of deep sea neutrino telescopes Multidisciplinary (Earth and Sea Science) Lines : 12 PMTs : 885 Next Generation : KM3NeT S. Adrian- Martines et al., Letter of Intent for KM3NeT 2.0, J. Phys. G 43 (2016) 084001 Lines : 115 + 230 PMTs : 64170 + 128340 Improved Technology Multi-site 3 / 24

The KM3NeT Collaboration ORCA : O scillation R esearch with C osmics in the A byss (KM3NeT-Fr) ARCA : A stroparticule R esearch with C osmics in the A byss (KM3NeT-It) 51 institutes and groups 41 cities 15 countries 250 people Two detectors ô Same Technology 4 / 24

Digital Optical Module (DOM) DOM : 43 cm of diameter 31 x 3” PMTs Directional Information 4 π sr coverage Main background : 40 K All data to shore KM3NeT (1 Gb. s ´ 1 / DOM) PMT : Digital Photon Counting Light concentrator ring Time-over-Threshold measurements ANTARES 5 / 24

Event topologies in a neutrino telescope 6 / 24

Oscillation Research with Cosmics in the Abyss (ORCA) KM3NeT-Fr Site : offshore Toulon (France) Main research : neutrino mass hierarchy ñ More details in the following Few to hundreds of GeV neutrinos Depth of 2500 m ~ 2 ORCA block : 0 0 115 lines m 23 m horizontal spacing 18 floors 9 m vertical spacing 8 Mton instrumented 7 / 24

Astroparticle Research with Cosmics in the Abyss (ARCA) KM3NeT-It Site : offshore Capo Passero (Sicily-Italy) Main research : high energy neutrino astronomy ñ More details in the following GeV to PeV neutrinos sources Depth of 3500 m ~ ARCA block (x2) : 7 0 0 115 lines m 90 m horizontal 36 m vertical 0.5 Gton instrumented ñ ORCA : 8 Mton ñ ANTARES : 15 Mton ANTARES 8 / 24

Production Chain : DOM and line integration Line Integration : DOM Integration : 8 DOM integration sites (in Netherland, Italy, Germany, Greece, 6 line integration sites (in Italy, France and Marocco) Germany, and France) Assembling of all components Assembling of all components (PMTs, electronics, PMTs 3D (DOM, line base, cables, line support, glass sphere, optical gel) structure, buoy) QA/QC tests QA/QC tests 9 / 24

Deployment of a Line Line furled around spherical frame | Position accuracy : „ 1 m 10 / 24

Inspection on the seabed (ROV) 11 / 24

Connection to the Network (ROV) 12 / 24

Unfurling of the Line Acoustic signal emitted after connection to the network checked 13 / 24

Inspection of the Line (ROV) 14 / 24

Data taking Examples of recorded events for ORCA (left) and ARCA (right) 15 / 24

Timeline and Costs Cost per line : „ 300k e 16 / 24

Calibration Technics Thousands of Digital Optical Modules (DOM). Performance of KM3NeT : relies on precise timing and positioning of all detector elements. Complete set of instruments and tools : ñ Calibration Base ñ Instrumentation Line ñ Muons ñ 40 K ñ Nanobeacons ñ Acoustics 17 / 24

Acoustic Positioning System DOM position must be known to properly reconstruct tracks and showers Measurement accuracy : „ 10 cm The Long Base-Line : Hydrophones on Calibration Base and Line Base Absolute positions known Reference system Acoustic Beacons on CB and LB On each DOM : Digital Acoustic Receiver 18 / 24

Optical Backgrounds and Nanobeacons DOM efficiency Internal DOM calibration 19 / 24

Calibration Unit Instrumentation line : Calibration base : Light and sound transmission Laser Beacon : Monitor full water column ñ Time calibration (<ns) Measurement every 20 minutes ñ Water optical properties. Current meter Hydrophone : position of the CB on the seafloor Sound Velocimeter Acoustic Long Baseline emitter CTD probe : Conductivity, for DOM positioning Temperature and Depth 20 / 24

ARCA : science program Provide complementary measurement of IC flux All neutrino flavour astronomy Multimessenger (continous data taking over 4 π sr) New unknown sources Galactic sources Check neutrino emission from : ñ Galactic plane (3 σ in 1.3 years) ñ RXJ1713 (3 σ in 4 years) ñ VelaX (3 σ in 2.5 years) 21 / 24

ORCA : main science program Main goal : neutrino mass hierarchy (NMH) Important for theory, cosmology, 0 νββ ñ Sensitivity better than 3 σ in 4 years ORCA optimised for GeV atmospheric neutrinos Probe matter effect on ν survival and appearance probabilities with Up-Going muons 22 / 24

ORCA : other science topics Improvement of measurement of ∆ m 2 32 and θ 23 Indirect search for low mass dark matter Supernovae monitoring Earth sciences : tomography, seismology Sea sciences : oceanography, bioacoustics, bioluminescence 23 / 24

Conclusion and outlooks ñ Two next-generation neutrino telescopes in the Mediterranean sea New innovative and effective design for the Digital Optical Module : ñ Increase in photo-cathode area ñ Directional Information and 4 π sr coverage Complete set of precise calibration instruments KM3NeT/ARCA can observe high energy neutrino flux seen by IceCube at the South Pole with : ñ A different field of view ñ Different systematic uncertainties KM3NeT/ORCA oscillations with atmospheric neutrinos : ñ NMH with a sensitivity of >3 σ in 4 years of operation 24 / 24

Backups 25 / 24

ANTARES dimensions 26 / 24

Specification of the PMTs 27 / 24

PMTs 28 / 24

ARCA/ANTARES angular resolution 29 / 24

ORCA tracks and shower identification 30 / 24

ARCA point-like source ( 9 E ´ 2 spectrum) 31 / 24

PMT Coincidences Rates 32 / 24

ORCA Dark Matter Phys. Lett. B, 759, 2016, 69-74 33 / 24

ORCA NMH sensitivity 34 / 24

Calibration Base Laser Beacon : ñ Time calibration (<ns) ñ Water optical properties. Hydrophone : position of the CB on the seafloor Acoustic Long Baseline emitter for DOM positioning (+ acoustic receiver on each DOM) 35 / 24

Instrumentation Line To monitor environmental conditions : Light and sound transmission affected Monitoring of the full water column Measurement every 20 minutes Height adapted to ARCA/ORCA Same instruments at different depths Current meter : Inclination of the lines Sound Velocimeter CTD probe : Conductivity, Temperature and Depth ñ Infer sound velocity through seawater equation of state 36 / 24